Tool assembly for surgical stapling device

ABSTRACT

The present invention includes a tool assembly with a first jaw movable in relation to a second jaw between a spaced position and an approximated position. An approximation member is movable in relation to the first jaw to effect movement of the first and second jaws from the spaced position to the approximated position. A cam channel is configured to approximate the distal ends of the first and second jaws prior to approximation of the proximal ends of the first and second jaws. An articulation and firing actuator includes a flexible band having first and second end portions, wherein movement of either the first or the second end portion of the band effects pivoting of the tool assembly, and movement of the both end portions of the band, simultaneously, effects movement of a dynamic clamping member to eject staples from a cartridge assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a National Stage Application of PCT/US03/31653 under 35 USC§371(a), which claims priority of U.S. Provisional Patent ApplicationSer. No. 60/416,056 filed Oct. 4, 2002, entitled “Tool Assembly forSurgical Stapling Device”, now abandoned, the disclosures of which arehereby incorporated by reference in their entirety.

BACKGROUND

1. Technical Field

The present disclosure relates generally to a surgical tool assembly formanipulating and/or applying fasteners to tissue. More specifically, thepresent disclosure relates to a surgical tool assembly having a pair ofjaws including a unique approximation mechanism to facilitate improvedclamping and manipulation of tissue.

2. Background of Related Art

Surgical staplers and tool assemblies for clamping tissue betweenopposed jaw structure of a tool assembly and thereafter fastening theclamped tissue are well known in the art. These devices may include aknife for incising the fastened tissue. Such staplers havinglaparoscopic or endoscopic configurations are also well known in theart. Examples of endoscopic surgical staplers of this type are describedin U.S. Pat. Nos. 6,330,965, 6,250,532, 6,241,139, 6,109,500 and6,079,606, all of which are incorporated herein by reference in theirentirety.

Typically, such staplers include a tool member or assembly having a pairof jaws including a staple cartridge for housing a plurality of staplesarranged in at least two laterally spaced rows and an anvil whichincludes a plurality of staple forming pockets for receiving and formingstaple legs of the staples as the staples are driven from the cartridge.The anvil and cartridge are pivotally supported adjacent each other andare pivotable in relation to each other between open and closedpositions. In use, tissue is positioned between the jaws in the openposition and the jaws are pivoted to the closed position to clamp tissuetherebetween.

One problem associated with conventional staplers and tool assemblies isthat as the anvil and cartridge pivot in relation to each other, closureoccurs first at the proximal end of the jaws and thereafter at thedistal end of the jaws. This sequence of jaw closure has the effect ofmoving tissue positioned between the jaws towards the distal end of thejaws, thus, forcing tissue from the jaws.

During laparoscopic or endoscopic procedures, access to a surgical siteis achieved through a small incision or through a narrow cannulainserted through a small entrance wound in a patient. Because of thelimited area available to access the surgical site, endoscopic staplersare sometimes used to grasp and/or manipulate tissue. Conventionalstaplers having an anvil or cartridge mounted to a fixed pivot pointwhich are pivotable to a closed position are not particularly suited forgrasping tissue because only a limited clamping force is produced at thedistal end of the jaws.

Accordingly, a need exists for an endoscopic surgical stapling toolmember or assembly having pivotal jaws which can be operated toeffectively grasp, manipulate and/or fasten tissue, including with theend of the jaws, without, or while minimizing, distal movement of thetissue positioned between the jaws.

SUMMARY

In accordance with the present disclosure, a tool assembly having a pairof jaws is disclosed. Each of the jaws has a proximal end and a distalend and the first jaw is movable in relation to the second jaw between aspaced position and an approximated position. First and second camfollowers are supported on the first jaw. An approximation member ismovable in relation to the first jaw and includes at least one camsurface positioned to engage the first and second cam followers. Theapproximation member is movable in relation to the first jaw to move theat least one cam surface in relation to the first and second camfollowers to effect movement of the first and second jaws from thespaced position to the approximated position. The at least one camchannel is configured to approximate the distal ends of the first andsecond jaws prior to approximation of the proximal ends of the first andsecond jaws. By approximating the distal ends of the first and secondjaws first, tissue positioned between the jaws is not pushed forwardwithin the jaws during closure of the jaws. Further, the jaws are betterable to grip and manipulate tissue using the distal ends of the jaws.

Preferably, the first jaw includes an anvil and the second jaw includesa cartridge assembly housing a plurality of staples. In a preferredembodiment, the at least one cam surface includes first and second camchannels, and the approximation member includes a flat plate having thecam channels formed therein. The first jaw includes a longitudinal slotformed in its proximal end and the approximation member is beingslidably positioned in the longitudinal slot. The first and second camfollowers are supported on the proximal end of the first jaw and extendacross the longitudinal slot adjacent the first and second cam channels.The first cam follower extends through the first cam channel and thesecond cam follower extends through the second cam channel. Preferably,the tool assembly is pivotally attached to a body portion by anarticulation joint. The body portion may form the distal end of asurgical stapling device or a proximal portion of a disposable loadingunit.

In another preferred embodiment, the tool assembly includes an anvil, acartridge assembly housing a plurality of staples and a dynamic clampingmember. The anvil and cartridge assembly are movable in relation to eachother between spaced and approximated positions. The dynamic clampingmember is movable in relation to the anvil and the cartridge assembly toeject the staples from the cartridge assembly. The tool assembly ispivotally attached to a body portion and is pivotable in relation to thebody portion from a position aligned with the longitudinal axis of thebody portion to a position oriented at an angle to the longitudinal axisof the body portion. An articulation and firing actuator extends atleast partially through the body portion and the tool assembly. Thearticulation and firing actuator is operably associated with the dynamicclamping member and the tool assembly and is movable in relation theretoto selectively pivot the tool assembly in relation to the body portionand/or move the dynamic clamping member in relation to the tool assemblyto eject the staples from the cartridge.

Preferably, the articulation and firing actuator includes a flexibleband having a first end portion extending at least partially through thebody portion and through the cartridge assembly, a central portionextending from the first end portion operably associated with thedynamic clamping member and a second end portion extending from thecentral portion through the cartridge assembly and at least partiallythrough the body portion to a position adjacent the first end. Thearticulation and firing actuator is operably associated with the toolassembly such movement of either the first end portion or the second endportion of the flexible band proximally and independently of the otherend portion effects pivoting of the tool assembly in relation to thebody portion, and movement of both the first and second end portions ofthe flexible band simultaneously effects movement of the dynamicclamping member to eject the staples from the cartridge assembly. In apreferred embodiment, an approximation member is operably associatedwith the tool assembly and is movable in relation to the tool assemblyto move the anvil and cartridge assembly from the spaced to theapproximated position.

BRIEF DESCRIPTION OF THE DRAWINGS

Various preferred embodiments of the presently disclosed tool assemblyfor use with a surgical stapling device are disclosed herein withreference to the drawings, wherein:

FIG. 1 is a side perspective view of one preferred embodiment of thepresently disclosed tool assembly in the approximated position;

FIG. 2 is a side view of the tool assembly shown in FIG. 1;

FIG. 3 is a side, exploded perspective view of the tool assembly shownin FIG. 1;

FIG. 4A is a schematic view of the jaws of the tool assembly shown inFIG. 1 at a first stage of jaw approximation;

FIG. 4B is a schematic view of the jaws shown in FIG. 4A at a secondstage of jaw approximation;

FIG. 4C is a schematic view of the jaws shown in FIG. 4B in anapproximated position;

FIG. 5 is a side perspective view of another preferred embodiment of thepresently disclosed tool assembly in the approximated position;

FIG. 6 is a side, exploded perspective view of the tool assembly shownin FIG. 5;

FIG. 7 is a side perspective view of the approximation member of thetool assembly shown in FIG. 6;

FIG. 8 is a side perspective view of the dynamic clamping member of thetool assembly shown in FIG. 6;

FIG. 9 is a top partial cross-sectional view with portions broken awaylooking through a portion of the cartridge assembly and showing thearticulation and firing actuator of the tool assembly shown in FIG. 6;and

FIG. 10 is a cross-sectional view with portions removed and portionsadded, as would be seen along section lines 10-10 of FIG. 9.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the presently disclosed tool assembly for astapling device will now be described in detail with reference to thedrawings in which like reference numerals designate identical orcorresponding elements in each of the several views.

FIGS. 1-3 illustrate one preferred embodiment of the presently disclosedtool assembly shown generally as 10 for use with a surgical staplingdevice. Tool assembly 10 includes a pair of jaws including an anvil 12and a cartridge assembly 14 and an approximation member 16. Cartridgeassembly 14 includes a support channel 18 for receiving a staplecartridge 14 a. Support channel 18 includes distal open channel portion18 a and a proximal portion 18 b defining a truncated cylinder 18 c.Although not shown in detail, staple cartridge 14 a houses a pluralityof staples and can include conventional pushers (not shown) fortranslating movement of a staple drive assembly that typically includesa sled (e.g., 131 in FIG. 6) to movement of the staples through openingsor slots in a tissue engaging surface 25 of cartridge 14 a.

Anvil 12 has a tissue engaging surface 20 having a distal end 20 a and aproximal end 20 b and a proximal body portion 22. A longitudinal slot 24extends along the central longitudinal axis of anvil 12 through tissueengaging surface 20 and is dimensioned to slidably receive a portion ofa drive assembly. The drive assembly typically includes a drive bar, aclosure assembly, a sled, and a plurality of pushers. The drive assemblyfunctions to eject staples from the cartridge and preferably alsomaintains a desired uniform tissue gap between the cartridge and theanvil during firing of the device. Proximal body portion 22 of anvil 12is dimensioned to be generally pivotably received within truncatedcylinder 18 c of proximal portion 18 b of support channel 18 such thattissue engaging surface 20 of anvil 12 is pivotable from a positionspaced from tissue engaging surface 25 of cartridge 14 a to anapproximated position in juxtaposed alignment therewith.

Tool assembly 10 includes an approximation member 16 having one or morecam channels 28 and 30. Preferably, approximation member includes a pairof cam channels although a single cam channel having a pair of camsurfaces is envisioned. Approximation member 16 is dimensioned to belinearly slidable through proximal portion 18 b of channel 18 andthrough a slot 22 a formed in proximal body portion 22 of anvil 12. Acam follower 32 extends through a bore 34 formed in proximal portion 22of anvil 12 and through a hole 35 in proximal portion 18 b of supportchannel 18 and is positioned within cam channel 28. A cam follower 36extends through a second bore 38 formed in the proximal portion 22 ofanvil 12 and through a hole 39 in proximal portion and is positionedwithin cam channel 30. When approximation member 16 is advanced throughslot 22 a in proximal portion 22 of anvil 12, cam followers 32 and 36move through cam channels 28 and 30, respectively. Since approximationmember 16 is confined to linear movement within slot 22 a, movement ofapproximation member 16 in a distal direction effects pivotal movementof anvil 12 from the open or spaced position to the closed orapproximated position. The angles of the cam slots can be configured toprovide a great variety of approximation motions to improve mechanicaladvantage and achieve specific results, e.g., grasping of tissue.

Referring also to FIGS. 4A-4C, cam channels 28 and 30 preferably areconfigured to pivot anvil 12 from an open position (FIG. 4A) towardscartridge assembly 14 in a controlled manner to initially facilitategrasping of tissue and thereafter provide for substantially parallelclosure of the anvil and cartridge assembly. More specifically, camchannels 28 and 30 are preferably configured to position the distal end20 a of tissue contact surface 20 of anvil 12 substantially in contactwith cartridge 14 (FIG. 4B) during the initial portion of an actuatingstroke of approximation member 16. This facilitates grasping of tissueeven very thin tissue. During a second portion of the actuating strokeof approximation member 16, distal end 20 a of anvil 12 is moved awayfrom cartridge assembly 14 to a resultant position in which tissueengaging surface 20 of anvil 12 is parallel or substantially parallel totissue engaging surface 25 of cartridge assembly 14. During the finalportion of the actuating stroke of approximation member 16, the anvil 12and cartridge assembly 14 are brought together in parallel orsubstantially parallel closure to define a desired tissue gap (FIG. 4C).It is noted that any desired motion of anvil 12 can be achieved usingthe cam followers described herein. By moving anvil 12 in relation tocartridge assembly 14 from the spaced to the approximated position inthe manner described above i.e., front or distal to back or proximalclosure, the tendency for tissue to move forward within the jaws, as inconventional devices, is substantially eliminated.

Although approximation member 16 is illustrated as being in the form ofa plate with two distinct cam channels, differently configuredapproximation members are envisioned. For example, a single cam channelmay be provided to engage two cam followers. Further, the cam channelsneed not be confined but rather can be formed on the surface of a plate,bar or the like. In such a device, the anvil may be urged by a biasingmember to the closed or clamped position.

Although one or more actuators has not been disclosed to advance theapproximation member and/or fire staples from the cartridge assembly, itis envisioned that one or more of a variety of known pivotable,rotatable, or slidable actuators, e.g., trigger, knob, lever, etc., maybe used to approximate the presently disclosed cartridge assembly and/orfire staples from the cartridge. It is also noted that the disclosedtool assembly may be or form the distal portion of a disposable loadingunit or may be incorporated directly into the distal end of a surgicalinstrument, e.g., surgical stapler, and may include a replaceablecartridge assembly.

FIGS. 5-10 disclose another preferred embodiment of the presentlydisclosed tool assembly shown generally as 100. Tool assembly 100includes an anvil 112 and a cartridge assembly 114, an approximationmember 116, and an elongated body portion 120 including an articulationjoint generally referred to as 122. Elongated body portion 120 may formthe proximal end of a disposable loading unit or the distal end of asurgical stapling device. Tool assembly 100 also includes a combinedarticulation and firing actuation mechanism 124 for articulating toolassembly 100 about articulation joint 122 and ejecting staples fromcartridge assembly 114. Although the articulation joint illustrated as aflexible corrugated member with preformed bend areas, articulation joint122 may include any known type of joint providing articulation, e.g.,pivot pin, ball and socket joint, a universal joint etc.

Approximation member 116 is substantially similar to approximationmember 16 and also includes cam channels 128 and 130 (FIG. 7).Approximation member 116 further includes a pair of guide channels 126.Guide channels 126 are dimensioned to receive guide pins 128 whichextend through elongated body portion 120 and function to maintainapproximation member 116 along a linear path of travel. Approximationmember 116 is constructed from a flexible material, e.g., spring steel,which is capable of bending around articulation joint 122. Alternately,it is envisioned that approximation member 116 may include a resilientrod, band or the like with cam surfaces formed thereon. Approximationmember 116 operates in substantially the same manner as approximationmember 16 and will not be discussed in further detail herein.

Cartridge assembly 114 includes a support channel 118, a sled 131 and adynamic clamping member 132 which, preferably, includes an upper flange134 a for slidably engaging a bearing surface of the anvil and lowerflange 134 b for slidably engaging a bearing surface of the cartridge. Aknife blade 134 is preferably supported on a central portion 134 c ofdynamic clamping member 132 to incise tissue. Knife blade may be securedto dynamic clamping member 132 in a removable or fixed fashion, formedintegrally with, or ground directly into dynamic clamping member 132.Sled 131 is slidably positioned to translate through cartridge 114 in aknown manner to eject staples from the cartridge. Sled 131 or the likecan be integral or monolithic with dynamic clamping member 132. Sled 131is positioned distal of and is engaged and pushed by dynamic clampingmember 132. The position of 131 is to effect firing or ejection of thestaples to fasten tissue prior to cutting the stapled tissue. Flange 134b preferably is positioned within a recess 138 formed in the base ofcartridge 114. Flange 134 a is preferably positioned within a single orseparate recess formed in anvil 112. Again, flanges 134 a and 134 b neednot be positioned in a recess but can slidably engage a respectivesurface of the anvil and cartridge. Dynamic clamping member 132preferably is positioned proximal of sled 130 within cartridge assembly114. Dynamic clamping member 132 functions to provide, restore and/ormaintain the desired tissue gap in the area of tool assembly 100adjacent sled 130 during firing of staples.

It is preferred that the anvil and preferably the dynamic clampingmember be formed of a material and be of such a thickness to minimizedeflection of the anvil and dynamic clamping member during firing of thedevice. Such materials include surgical grade stainless steel. The anvilis preferably formed as a solid unit. Alternatively, the anvil may beformed of an assembly of parts with conventional components.

Referring to FIGS. 6, 9 and 10, articulation and firing mechanism 124includes a tension member 140 which can have loops 124 or otherconnection portions or connectors for connection to suitable connectionmembers of one or more actuators or of an actuation mechanism. Althoughillustrated as a flexible band, tension member 140 may be or include oneor more of any flexible drive member having the requisite strengthrequirements and being capable of performing the functions describedbelow, e.g., a braided or woven strap or cable, a polymeric material, apara-aramid such as Kevlar™, etc. Kevlar™ is a trade designation ofpoly-phenyleneterephthalamide commercially available from DuPont. A pairof suitable fixed or rotatable members, preferably rollers 142 a and 142b, are secured at the distal end of cartridge assembly 114. Rollers 142a and 142 b may be formed or supported in a removable cap 114 b (FIG. 6)of cartridge assembly 114. Alternately, cap 114 b may be formedintegrally with staple cartridge 114 a or cartridge channel 118. Rollers142 a and 142 b can also be secured to or formed from cartridge supportchannel 118. Tension member 140 extends distally from elongated body 120of tool assembly 100, distally through a peripheral channel 142 instaple cartridge 114 a, around roller 142 a, proximally, preferably,alongside central longitudinal slot 144 formed in cartridge 114 a,through a slot 200, preferably a transverse slot, in or around aproximal portion of dynamic clamping member 132, distally around roller142 b, and again proximally through a channel 146 formed in cartridge114 a to a proximal portion of elongated body 120. Alternately, twotension members can be employed, each of which may be secured to dynamicclamping member 132. As illustrated in FIG. 10, channels 142 and 146 canbe at least partly defined by an inner and/or outer wall of cartridge114 a and/or by cartridge support channel 118. Unlike as shown, channels142 and 146 should be in a consistent, i.e., same, functionally same orcorresponding location on both sides of the staple cartridge. Thus, itis envisioned that there would be two peripheral channels 142, or twochannels 146.

In use, when a first end or portion 150 of tension member 140 isretracted by suitable means in the direction indicated by arrow “A”, asviewed in FIG. 9, tool assembly 100 will articulate about pivot member122 a in the direction indicated by arrow “D”. When second end orportion 152 of tension member 140 is retracted in the directionindicated by arrow “B”, tool assembly 100 will articulate in thedirection indicated by arrow “C”. When both ends of tension member 140are retracted simultaneously, tension member 140 will advance dynamicclamping member 132 distally through slot 144 in cartridge 114 a toadvance dynamic clamping member 132 and sled 130 through cartridge 114 aand by engaging pushers, eject staples from the cartridge and incisetissue in the tissue gap. In order to prevent dynamic clamping member132 from advancing through slot 144 when the tool assembly is beingarticulated, i.e., when only one end of tension member 140 is retracted,a lockout device (not shown), e.g., a shear pin, may be provided toprevent movement of the dynamic clamping member or delay it until apredetermined force has been applied to the dynamic clamping member. Itis envisioned that multiple tension members, e.g., bands, can beemployed, respectively, to perform individual or a combination offunctions. For example, a pair of tension members can be employed, oneto articulate, and the other to approximate, clamp and fire. The tensionmembers can be fixed to the dynamic clamping member or a knife carryingmember or to a combination dynamic clamping member, knife member and/orsled member.

The above-described tool assembly may be incorporated into a disposableloading unit such as disclosed in U.S. Pat. No. 6,330,965 or attacheddirectly to the distal end of any known surgical stapling device.Although a handle assembly for actuating the approximation member andthe combined articulation and firing mechanism have not beenspecifically disclosed herein, it is to be understood that the use of abroad variety of different actuating mechanisms and handleconfigurations are envisioned including toggles, rotatable and slidableknobs, pivotable levers or triggers, pistol grips, in-line handles,remotely operated systems and any combination thereof. The use of anabove-described tool assembly as part of a robotic system is envisioned.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, although this applicationfocuses primarily on the use of surgical staples, other fasteningdevices, such as two-part fasteners, may be included in this device. Ina device in which two-part fasteners are used, each of the anvil stapleforming pockets may be configured to receive one part of the two-partfastener. Further, it is envisioned that the teachings provided in thisdisclosure may be incorporated into surgical devices other than staplingdevices including graspers. Therefore, the above description should notbe construed as limiting, but merely as exemplifications of preferredembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the claims appended hereto.

1. A tool assembly comprising: a pair of jaws including a first jaw anda second jaw, each of the jaws having a proximal end and a distal end,the first and second jaws being movable in relation to the other; firstand second cam followers supported on the first jaw; and anapproximation member including at least one cam surface positioned toengage the first and second cam followers, the approximation memberbeing movable through an actuating stroke to move the at least one camsurface in relation to the first and second cam followers; wherein theapproximation member is movable to move the at least one cam surface inrelation to the first and second cam followers to effect movement of thefirst jaw to approximate a distal end of the first jaw with the secondjaw in a first portion of the actuating stroke, to subsequently move thedistal end of the first jaw away from the second jaw in a second portionof the actuating stroke, and to subsequently bring together the firstjaw and the second jaw in substantially parallel closure in a thirdportion of the actuating stroke.
 2. A tool assembly according to claim1, wherein the first jaw includes an anvil and the second jaw includes acartridge assembly, the cartridge assembly housing a plurality ofstaples.
 3. A tool assembly according to claim 1, wherein the at leastone cam surface includes at least one cam channel.
 4. A tool assemblyaccording to claim 3, wherein the at least one cam channel includesfirst and second cam channels.
 5. A tool assembly according to claim 1,wherein the approximation member includes a flat plate having the atleast one cam surface formed therein.
 6. A tool assembly according toclaim 5, wherein the first jaw includes a longitudinal slot formed inits proximal end, the approximation member being slidably positioned inthe longitudinal slot.
 7. A tool assembly according to claim 6, whereinthe first and second cam followers are supported on the proximal end ofthe first jaw and extend across the longitudinal slot adjacent the atleast one cam surface.
 8. A tool assembly according to claim 7, whereinthe at least one cam surface includes first and second cam channels, thefirst cam follower extending through the first cam channel and thesecond cam follower extending through the second cam channel.
 9. A toolassembly according to claim 1, further including a body portion, whereinthe tool assembly is pivotally attached to the body portion by anarticulation joint.
 10. A tool assembly according to claim 9, whereinthe body portion forms a distal end of a surgical stapling device.
 11. Atool assembly according to claim 1, wherein the body portion forms theproximal portion of a disposable loading unit.
 12. A tool assemblyaccording to claim 1, wherein the first jaw is an anvil and the secondjaw is a cartridge assembly housing including a plurality of staples.13. A tool assembly according to claim 12, further comprising: a bodyportion, wherein the tool assembly is pivotally attached to the bodyportion by an articulation joint; a dynamic clamping member beingmovable in relation to the anvil and the cartridge assembly to eject thestaples from the cartridge assembly; and an articulation and firingactuator extending at least partially through the body portion and thetool assembly, the articulation and firing actuator being operablyassociated with the dynamic clamping member and the tool assembly andbeing movable in relation thereto to selectively pivot the tool assemblyin relation to the body portion and move the dynamic clamping member inrelation to the tool assembly to effect ejection of the staples from thecartridge.
 14. A tool assembly according to claim 13, wherein thearticulation and firing actuator includes a flexible band having a firstend portion extending at least partially through the body portion andthrough the cartridge assembly, a central portion extending from thefirst end portion and being operatively associated with the dynamicclamping member and a second end portion extending from the centralportion through the cartridge assembly and at least partially throughthe body portion to a position adjacent the first end.
 15. A toolassembly according to claim 14, wherein actuation of the first endportion articulates the tool assembly in one direction and actuation ofthe second end portion articulates the tool assembly in an oppositedirection.